V10 4x4 runs bad bad!

[Joseph.Silverthorn]

Alight people I have a 87 V10 350 tbi bone stock with over 180 thousand miles. When you have the truck in reverse or any of the fwd gears the truck will die, but starts right back up. So I replaced the idle are sensor and the throttle postion sensor still the same promblem, so I then bought a set of headers and a new ac delco O2 sensor still that problem. Also replaced the egr valve and rebuilt the throttle body, new tdent cable also. Truck acts like it have no power and drinks gas less than 5 miles a gallon and is bone stock! Dont know what else to try it throws no codes please help. Also forgot to tell you that it has a tune up new everything and is timed correctly and wired correctly